EA021028B1 - Solid fuel burner - Google Patents

Abstract

Burner for conveyor gas propelled particulate solid fuel, said burner comprising a burner block (100) and an injector assembly (200), the injector assembly being at least partially surrounded by an injector passage (130) of the burner block, the injector assembly comprising an inner oxygen supply pipe (210) surrounding a fuel injector, which in turn surrounds an oxygen injector (230), each having a downstream end (211, 221, 231) on the side of the passage outlet, the inner oxygen supply pipe having a lateral surface onto which are mounted a set of lateral primary oxygen nozzles (212) for the injection of lateral jets of primary oxygen into the fuel injector with an injection orientation which follows a same sense of rotation around the longitudinal direction and which is directed towards the downstream end of the fuel injector, said lateral primary oxygen nozzles being positioned at a number of different distances from the downstream end (221) of the fuel injector.

Description

(57) A burner for fuel in the form of particles transported by a transport gas, comprising a burner unit (100) and a nozzle assembly (200), wherein the nozzle assembly (200) is at least partially surrounded by a nozzle channel (130) in the burner block, wherein the nozzle assembly comprises an internal oxygen supply pipe (210) surrounding the fuel nozzle, which in turn surrounds the oxygen nozzle (230), each of which has output ends (211, 221, 231) on the outlet side of the channel, the inner oxygen supply pipe (210) has a side surface on which has a plurality of side nozzles (212) for primary oxygen for supplying side jets of primary oxygen to the fuel nozzle, the feed orientation being in one direction of rotation around the longitudinal direction and which is directed to the output end of the fuel nozzle, with side nozzles for primary oxygen at many different distances from the output end (221) of the fuel injector.

The present invention relates to the field of burning particulate fuel, such as ground coal or coal dust, and more particularly, to the field of enriching transport gas with oxygen for such particulate fuel.

To increase the efficiency of the combustion process and / or limit the emission of nitrogen oxides, oxygen enrichment was proposed.

Oxygen enrichment of the gaseous fuel stream has been successfully applied in many industrial technological processes, such as glass melting, in lime and cement kilns, in steel production, and in many others.

Coal, on the other hand, is the most common fossil fuel currently available, and most of the world's electricity is produced by burning coal.

When using solid fuel particles, transport gas is often required to transport solid fuel particles from a storage or mill (e.g., a pulverized coal mill) to the burner.

Compared to oxygen enrichment of gaseous fuel streams, oxygen enrichment of a particle-loaded stream, such as a stream of coal dust in air, creates additional difficulties. These difficulties arise due to many factors described below.

Firstly, the enrichment of such a particle-loaded stream with oxygen creates a flammable or more easily flammable stream inside the burner, which requires very careful handling to prevent premature ignition, explosion, or other harmful effects.

Secondly, coal dust usually has an uneven distribution of particle sizes. Most coal-fired power plants use a fraction with a particle size of 75-120 microns. Under the influence of gravity, the trajectories of the coal particles in the stream loaded with particles deviate from the directions of the gas flow. Larger particles deviate more, while smaller particles more closely follow the direction of gas flow. In addition, a phenomenon called particle separation is observed on the bends of transport pipelines. As a result, the loading by particles is uneven over the cross section of the pipeline, and particles can even settle and accumulate at certain points in the pipeline.

A system for improving the combustion of a mixture of non-gaseous fuel and transport gas is known from νθ-Α-2006032961, comprising 1) a source of a mixture of non-gaseous fuel, in particular solid fuel and transport gas, 2) an oxygen source, 3) a burner operatively connected to the combustion chamber , 4) a fuel line in communication with a source of a mixture of non-gaseous fuel and transport gas, 5) a tubular oxygen spear in communication with an oxygen source, and 6) at least the first and second discharge elements in communication with an oxygen source but.

The fuel line of this system contains a section that extends along the axis towards the burner.

These at least first and second discharge elements are configured to pump and mix oxygen into the mixture stream in front of the burner or in the burner. At least one of the first and second injection elements receives oxygen from the spear. In addition, the first and second discharge elements are spaced from each other.

Using the system described above, first, a mixture of non-gaseous fuel and transport gas flows into the fuel line. Then, oxygen is supplied through the first and second injection devices so that oxygen and the mixture of non-gaseous fuel and transport gas are mixed. Then, oxygen, non-gaseous fuel and transport gas mixed in this way are burned in the combustion chamber.

Despite the principles of the system described in \ νϋ-Λ-2006032961. provide improved mixing of oxygen injected into the flow of a mixture of non-gaseous fuel and transport gas, which in turn leads to improved combustion, the practical implementation of such a system in an industrial environment met with a number of difficulties associated with the problems inherent in the combustion of solid fuel.

Indeed, the range of particulate fuels for industrial use is very wide. Even for a particular type of particulate fuel, such as coal dust, parameters such as average particle size, particle size distribution, composition, humidity, volatiles, bound nitrogen, etc., can be quite different from batch to batch and Each of these parameters affects the behavior of solid fuels during combustion.

The main disadvantage of the system known from νθ-Α-2006032961 is the lack of flexibility. Indeed, it is necessary to design and produce different systems optimized for each type of fuel in the form of particles. This significantly increases the cost of the system and does not allow the use of the system for burning fuel in the form of particles with a different particle size and different composition.

Another disadvantage of the system known from νθ-Α-2006032961 is the relatively high cost of maintenance. Indeed, particle-loaded streams, such as coal dust / air streams, are highly abrasive and expose any elements, such as oxygen spears and nozzles protruding into the particle-loaded stream, to substantial wear, which ultimately leads to malfunction and a substantial risk of premature ignition and explosion. To prevent this, in a system known from νθ-Α- 1 021028

2006032961, it is necessary to regularly replace at least the entire oxygen enrichment structure that is present inside the fuel line and which is therefore subject to abrasion.

The objective of the present invention is to provide an improved burner, suitable for practical implementation in an industrial environment, operating on the principle of injecting oxygen into a mixture of transport gas and fuel in the form of particles at many points spaced apart in front of the combustion chamber.

According to the present invention, there is provided a burner comprising a burner unit and a nozzle assembly.

The burner unit, which is usually made of ceramic refractory material, has an input face and an output face. Through the burner block in the longitudinal direction (hereinafter referred to as B1), the nozzle channel passes from the inlet in the inlet face to the outlet in the outlet face.

The nozzle assembly is usually made of metal having the appropriate heat resistance and corrosion resistance properties, and this assembly is at least partially surrounded by the nozzle channel. The nozzle assembly comprises an internal oxygen supply pipe, a fuel nozzle and an oxygen nozzle, each of which has an outlet end located on the side of the channel outlet.

The fuel nozzle at the outlet end has a feed nozzle for supplying particulate fuel driven by the transport gas towards the channel outlet. The fuel nozzle further surrounds the inner oxygen supply pipe near its outlet end.

An oxygen nozzle surrounds the fuel nozzle near its (i.e., oxygen nozzle) outlet end or, in other words, the output end of the oxygen nozzle surrounds the fuel nozzle. The oxygen nozzle also has an oxygen supply nozzle at the outlet end for supplying secondary oxygen around the fuel nozzle and towards the channel outlet.

The inner oxygen supply pipe has a side surface on which a plurality of primary oxygen nozzles are mounted. These side nozzles for primary oxygen are intended for supplying side jets of primary oxygen to the fuel nozzle, which, as described above, surrounds the inner oxygen supply pipe near its outlet end. The lateral nozzles for primary oxygen are located at many different distances from the output end of the fuel nozzle, and these distances are measured in the above longitudinal direction B1. The lateral nozzles of the primary oxygen have injection openings oriented to supply these lateral jets of primary oxygen with the orientation of the supply following in the same direction of rotation (i.e., clockwise or counterclockwise) around the longitudinal direction B1, in addition, this the orientation is directed to the outlet end of the fuel nozzle, i.e., to the outlet of the nozzle channel.

The primary oxygen side nozzles advantageously have a discharge opening oriented to supply a side stream of primary oxygen in an orientation substantially tangential to the side surface of the inner oxygen supply pipe. In particular, the discharge opening of the side nozzles for primary oxygen can be advantageously oriented for supplying a side stream of primary oxygen with a feed orientation that forms an angle α from 20 to 70 to the longitudinal direction B1. The lateral nozzles for supplying primary oxygen are preferably oriented so that the specified angle α to the longitudinal direction B1 corresponds to or is close to a predetermined angle θ (i.e., the angle θ of a certain value) so that the angle α falls into the range [θ-10 °, θ + 10 °].

The burner of the present invention advantageously comprises means for mounting the internal oxygen supply pipe in the fuel nozzle and for removing the internal oxygen supply pipe from the fuel nozzle, preferably for mounting and removing the internal oxygen supply pipe on the side of the inlet face of the block, i.e., on the so-called the cold side of the block.

The burner fuel feed pipe delivers particulate fuel driven by the transport gas to the fuel nozzle.

This fuel supply pipe essentially forms or defines a bend or bend in front of the fuel nozzle. In this case, the burner preferably comprises a pipe branch that is in line with the fuel nozzle and mounted on the fuel supply pipe on this elbow. Thus, the internal oxygen supply pipe can be installed in the fuel nozzle and removed from the fuel nozzle through this branch.

The burner is advantageously equipped with means for mounting side nozzles for primary oxygen on the side surface of the inner oxygen supply pipe and for removing side nozzles of the primary oxygen from the side surface of the inner oxygen supply pipe. Such a means is typically holes or perforations in the side wall of the inner oxygen supply pipe into which lateral primary oxygen nozzles can be inserted in the desired orientation. The number of openings may exceed the number of side nozzles of primary oxygen, in which case the openings without nozzles are blocked, for example, by a removable plug, so that such a removable plug is advantageously located substantially flush with the side surface of the inner oxygen supply pipe. Means

- 2 021028 for mounting the side nozzles for primary oxygen on the side surface of the inner oxygen supply pipe predominantly comprises a locking mechanism for locking the side nozzles for primary oxygen on the side surface of the inner oxygen supply pipe with a predetermined orientation of the injection hole, for example by screwing or snapping the nozzles into these holes, whereby the nozzle receiving part of the hole and the nozzle part entering the hole have a reciprocal shape.

Side nozzles for primary oxygen can be mounted at many different radial angles around the side surface of the inner oxygen supply pipe.

According to a particularly advantageous embodiment of the present invention, the inner oxygen supply pipe further comprises an end nozzle for primary oxygen located at the outlet end, through which oxygen can also be pumped. The end nozzle for primary oxygen in particular can be configured to pump primary oxygen towards the channel outlet in the longitudinal direction Ό1. It has been found that additional primary oxygen injection in the longitudinal direction Ό1 can improve stability and prevent flame failure. According to a particularly useful embodiment, the inner oxygen supply pipe comprises a central lance and a surrounding annular channel. The central spear ends at the end nozzle of the primary oxygen to which it is fluidly coupled. The surrounding annular channel is located between the side surface of the inner oxygen supply pipe and the central spear and is fluidly connected to the side nozzles for primary oxygen. In order to distribute primary oxygen between the central spear / end nozzle for primary oxygen on the one hand and the surrounding annular channel / side nozzles for primary oxygen on the other hand, the burner preferably comprises an oxygen distributor, and this oxygen distributor is separately fluidly connected to the central spear and with the surrounding annular channel. The oxygen distributor comprises means for connecting to an oxygen source. The oxygen distributor is further configured to control the relationship between the primary oxygen stream in the central spear and in the surrounding annular channel.

A swirl may be mounted in the fuel nozzle, typically on or adjacent to the fuel nozzle, and which is preferably mounted around an internal oxygen supply pipe. Such swirlers are known and used to create turbulence in a fluid, in this case, in a transport gas loaded with particulate fuel. When the swirl unit corresponds to a device that is affected by particulate fuel driven by the transport gas, the burner is preferably configured to install the swirl unit in the fuel nozzle and remove the swirl unit from the fuel nozzle together with the internal oxygen supply pipe or after the internal oxygen supply pipe will be removed from the fuel injector.

According to one embodiment of the present invention, the nozzle channel expands after the outlet ends, respectively, of the internal oxygen supply pipe, fuel nozzle, and secondary oxygen nozzle. Thus, in the nozzle channel near the outlet of the channel, an expanded pre-chamber combustion section is formed. The flame stability is improved and / or flame failure is prevented. The ratio between the length (in the longitudinal direction Ό1) and the diameter of the pre-combustion section is preferably from 0.6 to 1.0, preferably from 0.7 to 0.9. When the burner contains a wider section of the pre-combustion chamber, the outlet ends of the inner oxygen supply pipe and the fuel injector are preferably located in front of or adjacent to and in front of the extended section of the pre-combustion chamber at the beginning of the expanded pre-combustion section. The outlet end of the oxygen nozzle may also be located at this point, but it is useful to place it at a greater distance from the outlet of the nozzle channel.

The same or similar effect of increasing stability and preventing flame failure can be obtained by installing the burner in the wall of the combustion chamber or furnace so that the outer face of the burner block is recessed relative to the surface of this wall facing the combustion zone of this chamber or furnace, thereby creating a wider the pre-chamber section between the outer face of the burner block and the wall surface. As explained above, the ratio between the length and the diameter of the pre-combustion section is preferably 0.6-1.0, preferably 0.7-0.9.

Alternatively, the nozzle channel may be substantially cylindrical, in which case the outlet ends of the inner oxygen supply pipe, the fuel nozzle and the oxygen nozzle are advantageously located in front of the outlet of the channel.

As mentioned above, the outlet end of the oxygen nozzle may be upstream of the outlet end of the fuel nozzle.

The present invention also relates to a furnace having walls forming a combustion chamber and in which at least one burner according to any of the above-described variants is installed, mounted in the furnace wall so that the output face of the burner unit faces the combustion chamber and so that the input face The burner unit is accessible outside the combustion chamber.

As described above, according to one embodiment of such a furnace, at least one burner is installed in the wall of the furnace so that the outer face of the burner block is recessed relative to the surface of this

- 3 021028 of the wall facing the combustion chamber, thereby creating a wider section of the pre-chamber combustion between the output face of the burner block and the wall surface. The ratio between the length and diameter of the pre-combustion section is preferably 0.6-1.0, preferably 0.7-0.9.

The present invention relates in particular to tunnel kilns, boilers, rotary kilns and to furnaces and tunnel kilns.

The present invention further relates to the use of a burner according to any of the above options for burning solid fuel particles in a combustion zone of a furnace to produce heat. The particular solid fuel is preferably coal dust, but other particulate fuels such as petroleum coke, biomass particles, etc. can be used as solid fuel.

The present invention can, in particular, be advantageously used in an oven for the production of a wetting hardening binder such as cement, lime or gypsum.

Primary oxygen preferably has an oxygen content of at least 75 vol.%, Preferably at least 85 vol.% And more preferably at least 90 vol.%. The secondary oxygen may be air, but preferably with a higher oxygen content, as described above for primary oxygen.

The present invention and its advantages will be better understood from the following description of examples of specific embodiments with reference to the attached drawings.

Brief Description of the Drawings

FIG. 1 is a schematic perspective view of an embodiment of a burner according to the present invention.

FIG. 2 is a schematic side view of the burner of FIG. one.

FIG. 3 is a schematic section in the plane AA of the burner of FIG. 1 and 2.

FIG. 4 is a schematic section in the plane AA of the internal oxygen supply pipe of the specified burner.

FIG. 5 is a schematic front view of the burner of FIG. 1 and 2.

FIG. 6 is a schematic perspective view of a side nozzle for primary oxygen.

FIG. 7 is a schematic sectional view of the outlet end of an alternative burner embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Shown in the drawings, the burners of the present invention have a burner unit 100 (burner stone 100) and a nozzle assembly 200.

The burner unit 100 has an input face 110 and an output face 120. The block further comprises a nozzle channel 130 extending through the block from the input face 110 to the output side 120.

The nozzle channel 130 has a channel input 131 in the input face 110 and a channel output 132 in the output face 120.

In operation, the burner unit 100 is mounted or integrated into the walls of the combustion chamber so that the output face 120 faces the combustion zone inside the combustion chamber, and the input face 110 faces outward relative to the furnace and is substantially accessible from the outside of the combustion chamber to control the burner, its maintenance and repair.

The burner unit 100 is essentially made of refractory materials, in particular ceramic refractory materials.

In the embodiment shown in FIG. 1-5, the nozzle channel 130 comprises a wider pre-chamber combustion section 135 located adjacent to the channel exit 132. In the embodiment shown in FIG. 7, on the other hand, the nozzle channel 130 has a substantially constant diameter and does not contain an expanded pre-chamber combustion section.

In practice, particularly good flame stability and prevention of flame failure were achieved with pre-combustion sections in which the length to diameter ratio was from 0.6 to 1.0, more specifically from 0.7 to 0.9. The length of the pre-combustion section was preferably from 8 to 14 cm, more preferably from 9 to 12 cm.

In the embodiment of FIG. 1-4, the burner unit 100 is a unit consisting of two parts 136 and 137 made of refractory material. The inlet face 110 comprises a plurality of facets 110a, 110b, and 110c. The length of the pre-combustion section (in the longitudinal direction Ό1) is determined by the relative position of the two parts 136 and 137 of refractory material. In the embodiment of FIG. 7, the burner unit is made integrally from a single piece of refractory material. Entrance face 110 is a flat surface.

The nozzle assembly 200 comprises an inner oxygen supply pipe 210, a fuel nozzle 220, and an oxygen nozzle 230.

All output ends 211, 221 and 231, respectively, of the oxygen supply pipe 210, the fuel injector 220, and the oxygen nozzle 230 are located in the nozzle channel 130 of the burner unit 100. Fuel injector 220 has a fuel nozzle 222 located at its outlet end 221 and surrounding an inner oxygen supply pipe 210 at least adjacent to an outlet end 211 of this inner oxygen supply pipe to create a particulate propelled fuel stream transport gas around the inner oxygen supply pipe 210 and

- 4 021028 directed to the exit 132 of the channel for feeding from it into the combustion zone.

In the embodiments shown, the fuel feed nozzle 222 is a separate part mounted on the output end 221 of the fuel injector 220.

A swirl 229 is mounted on the fuel injector 220 near its outlet end 221. This swirl 229 surrounds the inner oxygen supply pipe 210.

Oxygen nozzle 230 at its outlet end 231 has a secondary oxygen supply nozzle 232. An oxygen nozzle 230 surrounds the fuel nozzle 220 at least near the outlet end 231 of the oxygen nozzle 230.

In operation, the oxygen nozzle 230 thus creates a stream of secondary oxygen around the fuel nozzle 220 and directed to the channel exit 132, for supplying it into the combustion zone through the wider section 135 of the pre-chamber combustion of the nozzle channel 132 when such a wider section is present.

In the illustrated embodiments, the secondary oxygen nozzle 232 is integrally formed with the outlet end 231 of the oxygen nozzle 230. In alternative embodiments, a separately formed secondary oxygen nozzle may be provided at this outlet end 231.

In the shown embodiments, the outlet end 231 of the oxygen injector 230 is located farther from the outlet 132 of the channel than the outlet end 211 and 221, respectively, of the inner oxygen supply pipe 210 and the fuel injector 220.

The outlet end 231 of the oxygen nozzle may be located closer to the outlet ends 211 and 221, but preferably does not protrude beyond these outlet ends 211 and 221.

In the region of its outlet end 211, the inner oxygen supply pipe 210 is centrally located in the fuel injector 220.

A plurality of side nozzles 212 for primary oxygen are mounted on the side surface of the inner oxygen supply pipe 210 by perforations 215 in this side surface. These primary oxygen side nozzles and corresponding perforations 215 are located at different distances from the outlet end 211 of the inner oxygen supply pipe 210.

During operation, these primary oxygen side nozzles 212 inject oxygen into the body of the fuel injector, thereby gradually enriching the transport gas as it moves the particulate fuel to the fuel nozzle nozzle 222 and to the channel exit 132.

The primary oxygen side nozzles 212 have a feed opening oriented so as to inject primary oxygen into the fuel nozzle 220 towards the channel exit 132, substantially tangential to the side surface of the internal oxygen supply pipe, and forming an angle α with the longitudinal direction Ό1 of the nozzle channel 130.

It should be understood that the angle α corresponds to the initial direction of the side stream of primary oxygen when it leaves the nozzle orifice and then:

(1) the direction of the jet of primary oxygen changes under the influence of a stream of fuel in the form of particles transported by the transport gas in the fuel nozzle, and (2) the primary oxygen supplied in this way mixes rapidly with the transport gas and enriches it.

The specific orientation of the supply of the side feed nozzles 212 for primary oxygen allows not only to gradually enrich the transport gas with oxygen, but also to do this without significantly increasing the pressure drop across the fuel injector 220 or even without any additional pressure drop across the fuel nozzle 220, despite that the side nozzles 212 for primary oxygen protrude into the trajectory of the fuel in the form of particles driven by the transport gas.

The feed orientation of the primary oxygen side nozzles 212 further prevents, restricts, or removes any significant particulate fuel deposits that may or may occur within the fuel injector 220 and thus provide a more homogeneous distribution of particulate fuel over the cross section of the fuel nozzle 220. It is contemplated that the protrusion of the side nozzles 212 for primary oxygen into the particle path of the fuel may actually help to limit or prevent significant solid fuel deposits due to the turbulence they create.

In the above examples, the angle α for all side feed nozzles for primary oxygen is the same.

In some specific cases, it may be useful to create different angles α for different side feed nozzles for primary oxygen in order to get the best, i.e. more homogeneous distribution of fuel in the form of particles in the fuel injector 220.

The longitudinal profile of the gradual oxygen enrichment of the transport gas as it flows through the fuel nozzle is determined by:

1) the longitudinal position of the side nozzles 212 for primary oxygen (the distance to the output end 211 of the inner oxygen supply pipe 210 or the distance to the output end 221 of the fuel injector 220) and

- 5 021028

2) the supply hole of the respective side nozzles 212 for primary oxygen, the cross section of which determines the proportion of primary oxygen supplied to the inner oxygen supply pipe 210, which is injected through individual nozzles 212 (a smaller hole restricts the flow of oxygen passing through it, compared to a wider feed hole )

As shown in FIG. 3, 4 and 5, the side nozzles 212 for primary oxygen and the corresponding perforations are also located in different radial positions (shown in Fig. 4 as clockwise measured angles θ1 = 0 °, θ2 = 90 °, θ3 = 180 ° and θ4 = 270 ° from the upward vertical). The radial position of the side nozzle 212 for primary oxygen can be optimized to prevent the occurrence of deposits of solid fuel and fuel-rich and fuel-depleted zones or corridors in the fuel nozzle 220, especially at its output end.

For example, when the probability of caking fuel in the form of particles is high, a greater number of side nozzles 212 for primary oxygen can be arranged so that they inject jets of primary oxygen under the inner oxygen supply pipe 210 and, possibly, across the top of this inner oxygen supply pipe, where the most probable fuel deposits.

In the embodiments shown, the inner oxygen supply pipe 210 further comprises a central oxygen lance 213, which ends with an end nozzle 216 for primary oxygen. In the shown embodiments, the end nozzle 216 of the central oxygen spear 213 injects primary oxygen in the longitudinal direction Ό 1 of the nozzle channel towards the channel exit. Other end nozzles for oxygen supply can be mounted on the central oxygen spear, possibly with different feed orientations or configurations.

An annular channel 214 is formed between the oxygen spear and the side surface of the inner oxygen supply pipe 210, which surrounds the central oxygen spear 213, with the primary oxygen side nozzles 212 communicating with this annular channel 214 through perforations 215.

Fuel injector 220 is in communication with a fuel supply line comprising an elbow 223 located in front of the fuel injector 220. A branch pipe 224 that is in line with the fuel injector 220 is installed on the fuel supply line on this elbow 223.

The inner oxygen supply pipe 210 exits the branch pipe 224 and enters the fuel injector 220.

An oxygen distributor 240 is located at the inlet end of the inner oxygen supply pipe 210. The oxygen distributor 240 comprises an inlet chamber 241 and two outlet chambers 242, 243. In operation, the inlet chamber 241 is connected to a primary oxygen source through an inlet 246. The first outlet chamber 242 communicates with the surrounding annular channel 214 of the inner oxygen supply pipe 210. The second output chamber 243 communicates with the central oxygen spear 213. The input chamber 241 communicates with the first output chamber 242 through the first channel 247. The input chamber 241 communicates with the second output chamber 243 through the second channel 248. The oxygen distributor 240 further comprises first and second means 247a and 248a to restrict the flow of primary oxygen, respectively, through the first and second channels 247, 248, respectively, into the first and second output chambers 242 and 243, and therefore, to restrict the flow of primary oxygen, respectively in fact, to the surrounding annular channel 214 and to the central oxygen spear 213. In particular, the flow of oxygen can be limited manually or automatically, by limiting the free cross-sectional area of the first and second channels, respectively. In a particularly flexible of the embodiments shown, a first screw 247a and a second screw 247a are used for the first and second primary oxygen flow restriction means, respectively. Alternatives include diaphragms and other adjustable valves.

In operation, oxygen flows from the primary oxygen source to the inlet chamber 241 of the oxygen distributor 240 through the inlet 246. This primary oxygen stream is then divided between the first and second output chambers 242 and 243 in a ratio determined by the position of the first and second primary oxygen flow restriction means. Primary oxygen then flows from the first outlet chamber 242 to the central oxygen spear 213 and then to the end nozzle 216, and from the second outlet chamber 243 to the surrounding annular channel 214 and then to the side nozzles 212 for primary oxygen.

According to an alternative embodiment (not shown), the first output chamber (communicating with the surrounding annular channel and, through this channel, with side nozzles) also functions as an input chamber, i.e. primary oxygen is supplied from the source of primary oxygen through the inlet to the first exhaust chamber. This first outlet chamber communicates with a second outlet chamber (which communicates with the internal oxygen spear and, through the internal oxygen spear, with the longitudinal nozzle) through the connecting channel. The oxygen distributor further comprises means for restricting the flow of primary oxygen from the first outlet chamber (inlet chamber) to the second outlet chamber.

The ratio (a) of the stream of primary oxygen flowing from the first outlet chamber to the second outlet chamber and then to the central oxygen spear to

- 6 021028 (b) the flow of primary oxygen flowing from the first outlet chamber directly to the annular channel and to the side nozzles in this (not shown) version is determined by the setting of these limiting means. This particular embodiment also allows the use of restrictive means for supplying primary oxygen only through the side nozzles for primary oxygen (when the connecting channel between the two output chambers is completely closed).

The nozzle assembly is mounted on an input face 110 of the burner unit 100 with a bracket (not shown) such that a part of the nozzle assembly after this input face is located inside the nozzle channel 130 in the block. The inner oxygen supply pipe 210 is detachably connected to the rest of the nozzle assembly 200 via a connector 260. The connector 260 is easily accessible and located on the cold side of the burner. Thus, the inner oxygen supply pipe 210 can be removed from the fuel nozzle 220 for inspection and maintenance or replacement from outside the furnace, i.e. outside the combustion zone. In addition, this can be done without stopping the oven. This is especially important in furnaces equipped with a large number of burners, for which maintenance is time consuming and for which interruption of production or shutdown of the furnace would be economically unacceptable.

When the inner oxygen supply pipe 210 is thus removed from the fuel injector 220, the primary oxygen side nozzles 212 (as well as any other nozzles or parts present on the inner oxygen supply pipe, such as the end nozzle 216) can be cleaned or replaced with an identical nozzle ( for example, when an existing nozzle is damaged as a result of the abrasive effect of particulate fuel). They can also be replaced with other nozzles (for example, nozzles with a different feed hole to change the relative flow of primary oxygen through the side nozzle in a specific position on the side surface of the inner oxygen supply pipe or to nozzles with a different supply direction) or replace existing nozzles with plugs, which are preferably flush with the side surface of the inner oxygen supply pipe 210, or vice versa.

The burner of the present invention is thus very flexible and can be adapted to the requirements for burning different types of fuel in the form of particles or solid fuels of different quality (particle size, volatile matter content, etc.), as well as changes in operating conditions furnace (total or local energy demand) by changing the degree and profile of oxygen enrichment of the transport gas along the fuel nozzle, the position and orientation of the side nozzles 212 for primary oxygen, etc.

The main advantage of the present invention is its flexibility. Indeed, the burner of the present invention is well adaptable. The burner can be used in a wide range of capacities, by adapting the flows of fuel driven by the transport gas, and the flows of primary and secondary oxygen. The burner can be used with different concentrations of fuel in the form of particles in the transport gas. More substantially, the burner of the present invention can be used for different types of particulate fuels, for example, fuels with different average particle sizes, fuels with different particle size distributions, and for chemically or physically different types of particulate fuels, including fuels with different content of combustible volatile substances or with different ash content, for fuel with different degrees of humidity, for coal dust, petroleum coke, ground waste, etc.

A particular advantage of the present invention is that a single burner can be used for such a wide range of combustion parameters and types of fuel. Indeed, in the burners of the present invention, the fuel consumption in the form of particles transported by the transport gas, primary oxygen and secondary oxygen can be controlled, thereby controlling, among other things, the degree of oxygen enrichment in the fuel in the form of particles transported by the transport gas and, in addition, the profile such oxygen enrichment along the fuel injector can be controlled by simply replacing the internal oxygen supply pipe or by changing the number and / or position and / or design of the side nozzles for the primary th oxygen of the inner tube of the oxygen supply of the burner.

In addition, the present invention allows to take into account various types of behavior of the captured fuel in the form of particles in the transport gas (for example, due to different particle sizes or different particle densities). Thus, it is possible to counteract the deposition or separation of particles by selecting the number, position, feed orientation, etc. side nozzles for primary oxygen.

As yet another highly relevant advantage of the present invention, ease and low cost of maintenance should be mentioned.

Burner maintenance is an important issue, in particular for particulate fuel burners, due to the abrasive effect that particles transported by the gas exert on the nozzles. The wear and tear caused by such particles can ultimately lead to perforation of the nozzle walls and to the subsequent risk of explosion, etc.

In an embodiment of the present invention, in which the inner oxygen supply pipe can be removed from the nozzle, while the rest of the nozzle remains in place in the burner unit and, in particular, when the inner oxygen supply pipe can be removed from the cold side of the inlet face of the unit, check the condition and maintenance of primary delivery nozzles, which are particularly at risk of corrosion, can be carried out easily and quickly and, if necessary, the internal oxygen supply pipe can be replaced to maintain safety.

In addition, in an embodiment of the present invention, in which side nozzles for primary oxygen can be removed from the side surface of the inner oxygen supply pipe to be replaced with other side nozzles for primary oxygen or plugs, as the case may be, in practice it is not even necessary to replace the inner pipe oxygen supply in case of increased risk of erosion. Instead, it can be quite simple to replace the primary oxygen side nozzles that have undergone significant erosion on the existing internal oxygen supply pipe, and then reinsert the internal oxygen supply pipe into the nozzle channel as described above.

Naturally, a similar procedure can be performed to replace or change the internal oxygen supply pipe in order to adapt it to changes in the parameters of the combustion process and, in particular, when the transport gas that moves the fuel in the form of particles changes.

To burn fuel in the form of particles, the temperature in the combustion chamber must be sufficiently high, due to the nature of such fuel. Thus, the cold firing of a particulate fuel furnace is not possible.

In order to eliminate such a difficulty, the solid fuel burner can be equipped with an auxiliary nozzle assembly comprising: (a) an auxiliary nozzle 240 for an oxidizing agent and (b) an auxiliary fuel nozzle 241, wherein the auxiliary fuel nozzle is connected to a source of gaseous or liquid fuel, preferably with a source of gaseous fuel.

The burner unit 100 may include an auxiliary nozzle channel 242 extending between the inlet face 110 and the outlet face 120, and in which the auxiliary nozzle assembly for supplying oxidizer and liquid and gaseous fuel to the combustion chamber is installed. A suitable position for the outlet of such a channel for the auxiliary nozzle is shown in FIG. 7.

During cold ignition of the furnace, the burner first operates using an auxiliary nozzle assembly to burn gaseous or liquid fuels to raise the temperature in the furnace. When the temperature in the combustion chamber reaches at least the minimum temperature necessary for the combustion of fuel in the form of particles, the burner starts to work using the nozzle assembly for fuel in the form of particles to burn this fuel, and the auxiliary nozzle assembly is switched off.

Although the use of the auxiliary nozzle assembly is described above with reference to the specific burner of the present invention, such auxiliary nozzle assembly can advantageously be integrated into other particulate fuel burners.

Example.

In the furnace containing the combustion chamber defined by the walls of the furnace, several burner blocks of the present invention are installed so that the output face of the burner blocks faces the combustion chamber and runs flush with the wall of the furnace in which this block is installed, and so that the input face of the block was facing away from the combustion chamber.

An oxygen nozzle and a fuel nozzle are installed in the nozzle channel of the burner unit, as described above. An oxygen nozzle is connected to an oxygen source, and a fuel nozzle is connected to a fuel source in the form of particles transported by a transport gas.

The lateral feed nozzles for primary oxygen are mounted on the internal oxygen supply pipe of each burner in a predetermined quantity, in predetermined axial and radial positions, along the internal oxygen supply pipe with a predetermined supply orientation. These parameters can be determined by preliminary tests and / or modeling.

The lateral feed nozzles for primary oxygen are installed on the inner oxygen supply pipe in the machined holes or perforations in the side wall of this pipe. Any such openings not occupied by the side nozzles for primary oxygen are blocked by similarly processed stoppers, which are flush with the side surface of the pipe.

The inner oxygen supply pipe is then installed in the fuel nozzle in the nozzle channel and connected to a source of primary oxygen.

When, as described above, the inner oxygen supply pipe comprises a central oxygen spear and an annular channel surrounding the spear, and a central oxygen spear, and the annular channel are connected to a primary oxygen source.

During operation, one or more control devices regulates the respective fuel flows in the form of particles transported by the transport gas, primary oxygen and secondary oxygen going to the burner, so that the control means can further control the primary oxygen flow to the central oxygen spear and the annular channel surrounding it .

If the temperature inside the combustion chamber is high enough, the collected burner can be immediately used to burn fuel in the form of particles, for example, coal dust.

However, if the burner is assembled in preparation for the cold ignition of the furnace, the combustion chamber is usually first heated to a sufficiently high temperature by one or more gas burners or a liquid fuel burner before operating the burner to burn fuel in the form

Claims (13)

CLAIM 1. A burner comprising a burner block (100) and a nozzle assembly (200), wherein the block (100) has an input face (110) and an output face (120), and a nozzle channel (130) extending in the longitudinal direction (Ό1) from the input (131) of the channel in the input face (110) to the output (132) of the channel in the output face (120); the nozzle assembly (200) at least partially surrounded by the nozzle channel (130) and containing an internal oxygen supply pipe (210), a fuel nozzle (220) and an oxygen nozzle (230), each of which has an outlet end (211, 221, 231) from the outlet side (132) of the channel, said fuel nozzle at its outlet end (221) has a nozzle (222) for supplying solid fuel in the form of particles transported by transport gas to the channel exit (132) and surrounds the inner pipe (210) oxygen supply near the output end (211) of the inner oxygen supply pipe The connected oxygen nozzle (230) at its output end (231) has a nozzle for supplying secondary oxygen to the channel outlet (132) and surrounds the fuel nozzle (220) near the output end (231) of the oxygen nozzle (230), while the inner pipe ( 210) the oxygen supply has a side surface on which a plurality of side nozzles (212) are installed for supplying side jets of primary oxygen to the fuel nozzle (220), while these side nozzles (212) for primary oxygen are located at a variety of different distances measured in the longitudinal direction ( Ό1) from the outlet end (221) of the fuel nozzle (220), and have a supply opening oriented for supplying said side jets of primary oxygen with a feed orientation following in the same direction of rotation around the longitudinal direction Ό1 and which is directed toward the outlet end (221 ) fuel injector (220). 2. The burner according to claim 1, in which the side nozzles (212) for primary oxygen have a feed opening oriented to supply a side stream of primary oxygen with a feed orientation substantially tangential to the side surface of the inner oxygen supply pipe (210). 3. A burner according to any one of the preceding claims, comprising means for installing an inner pipe (210) for supplying oxygen to a fuel nozzle (220) and for extracting an inner pipe (210) for supplying oxygen from a fuel nozzle (220). 4. A burner according to claim 3, comprising means for installing an inner pipe (210) for supplying oxygen to the fuel nozzle (220) and for extracting an inner pipe (210) for supplying oxygen from the fuel nozzle (220) from the inlet side (110) of the unit ( one hundred). 5. The burner according to claim 4, further comprising a fuel supply pipe for supplying fuel in the form of particles transported by the transport gas to the fuel nozzle (220), wherein the fuel supply pipe forms a bend (223) in front of the fuel nozzle (220), wherein the burner contains a branch pipe (224) located in line with the fuel nozzle (220) and mounted on the fuel supply pipe on the elbow (223), through which the internal oxygen supply pipe (210) can be installed in the fuel nozzle (220) and removed from fuel injector (220). 6. A burner according to any one of the preceding claims, comprising means for mounting side nozzles (212) for primary oxygen on the side surface of the inner pipe (210) of oxygen supply and for removing side nozzles (212) for primary oxygen from the side surface of the inner pipe (210) oxygen supply. 7. Burner according to any one of the preceding paragraphs, in which the side nozzles (212) for primary oxygen are located at many different radial angles (Θ1, Θ2, θ3, Θ4) around the side surface of the inner tube (210) of the oxygen supply. 8. A burner according to any one of the preceding claims, wherein the inner oxygen supply pipe (210) further comprises an end nozzle (216) for primary oxygen at its output end (211) for supplying primary oxygen. 9. A burner according to claim 8, in which the oxygen supply pipe comprises a central spear (213) ending with an end nozzle (216) for primary oxygen, which is in fluid communication with the central spear (213), and a surrounding annular channel (214) ) between the side surface of the inner tube (210) of the oxygen supply and the central spear (213), while the surrounding annular channel is fluidly connected to the side nozzles (212) for primary oxygen. 10. The burner according to claim 9, further comprising an oxygen distributor (240), separately fluidly connected to a central lance (213) and to the surrounding annular channel (214), the oxygen distributor comprising means for connecting the oxygen distributor (240) to - 9 021028 an oxygen source and is configured to control the relationship between the primary oxygen stream to the central spear (213) and the primary oxygen stream to the surrounding annular space (214). 11. The burner according to any one of the preceding paragraphs, having a wider section (135) of pre-chamber combustion located in the nozzle channel (130) near the outlet (132) of the channel. 12. A furnace containing walls forming a combustion chamber, at least one burner according to any one of claims 1 to 11, installed in the furnace wall so that the output face (120) of the burner block (100) faces the combustion chamber, and so, that the input face (110) of the burner unit (100) is accessible outside the combustion chamber. 13. A furnace containing walls forming a combustion chamber, at least one burner according to any one of claims 1 to 10, installed in the furnace wall so that the output face (120) of the burner block (100) is facing the combustion chamber, and so, that the input face (110) of the burner block (100) is accessible outside the combustion chamber, and at least one burner is installed in the specified wall of the furnace so that the output face (120) of the burner block (100) is recessed relative to the surface of the specified wall facing the combustion chamber , thereby forming a wider section of the pre-chamber burned I between the output face (120) of the block (100) and said surface of the burner wall.